LM3489MM Buck Regulator Controller Equivalent & Substitute Parts

Part Overview

The LM3489MM is a buck regulator positive output step-down DC-DC controller IC manufactured by Texas Instruments in 8-VSSOP packaging. This device functions as a transistor driver for step-down topology applications with a single output phase, operating across a supply voltage range of 4.5V to 35V with switching frequency up to 1MHz and 100% maximum duty cycle. The LM3489MM is classified as Last Time Buy, indicating production discontinuation. Identifying equivalent and substitute parts is necessary to ensure design continuity and maintain supply chain reliability for applications currently utilizing this controller.

Key Parameters

Parameter	Value
Manufacturer	Texas Instruments
Category	Power Management (PMIC)
Function	Step-Down Buck Regulator Controller
Output Type	Transistor Driver
Topology	Buck
Number of Outputs	1
Output Phases	1
Voltage Supply Range (Vcc/Vdd)	4.5V ~ 35V
Switching Frequency	Up to 1MHz
Duty Cycle (Max)	100%
Operating Temperature	-40°C ~ 125°C (TJ)
Package / Case	8-TSSOP, 8-MSOP (0.118", 3.00mm Width)
Mounting Type	Surface Mount
RoHS Status	ROHS3 Compliant
Moisture Sensitivity Level (MSL)	1 (Unlimited)

Substitute Part Grouping Explanation

Substitution of the LM3489MM is determined by strict equivalence across the following critical parameters:

Topology & Function: Buck regulator controller with transistor driver output
Electrical Specifications: Supply voltage range 4.5V ~ 35V, 100% duty cycle, single output phase
Package Compatibility: 8-VSSOP (8-TSSOP, 8-MSOP) surface mount package
Environmental & Compliance: Operating temperature -40°C ~ 125°C, ROHS3 compliance, MSL 1
Control Features: Current limit and enable functions (where specified)
Switching Frequency: Up to 1MHz operation (where specified)

Substitute parts are grouped into two categories:

Category A - Direct LM3489 Series Variants: Parts sharing the LM3489 base product number with identical electrical and control specifications. These include packaging variants (Cut Tape vs. Tape & Reel) and qualification grades (commercial vs. automotive AEC-Q100).

Category B - LM3485 Series Equivalents: Parts based on the LM3485 platform that maintain electrical parameter equivalence (supply voltage, topology, package, temperature range, duty cycle) but may differ in control feature specification and switching frequency documentation.

Parameter Comparison

Part Number	Manufacturer	Base Product	Vcc/Vdd Range	Duty Cycle Max	Package	Temp Range	Control Features	Switching Freq	Product Status	Inventory (Pcs)
LM3489MM	Texas Instruments	LM3489	4.5V ~ 35V	100%	8-VSSOP	-40°C ~ 125°C	Current Limit, Enable	Up to 1MHz	Last Time Buy	2,300
LM3489MM/NOPB	Texas Instruments	LM3489	4.5V ~ 35V	100%	8-VSSOP	-40°C ~ 125°C	Current Limit, Enable	Up to 1MHz	Active	15,700
LM3489MMX/NOPB	Texas Instruments	LM3489	4.5V ~ 35V	100%	8-VSSOP	-40°C ~ 125°C	Current Limit, Enable	Up to 1MHz	Active	16,371
LM3489QMM/NOPB	Texas Instruments	LM3489	4.5V ~ 35V	100%	8-VSSOP	-40°C ~ 125°C	Current Limit, Enable	Up to 1MHz	Active	10,684
LM3489QMMX/NOPB	Texas Instruments	LM3489	4.5V ~ 35V	100%	8-VSSOP	-40°C ~ 125°C	Current Limit, Enable	Up to 1MHz	Active	3,060
LM3485MM/NOPB	Texas Instruments	LM3485	4.5V ~ 35V	100%	8-VSSOP	-40°C ~ 125°C	Not specified	Not specified	Active	96,400
LM3485MMX/NOPB	Texas Instruments	LM3485	4.5V ~ 35V	100%	8-VSSOP	-40°C ~ 125°C	Not specified	Not specified	Active	55,100
LM3485Q1MM/NOPB	Texas Instruments	LM3485	4.5V ~ 35V	100%	8-VSSOP	-40°C ~ 125°C	Not specified	Not specified	Active	2,140

Engineering Selection Recommendations

Primary Substitutes (LM3489 Series - Active Status)

LM3489MM/NOPB, LM3489MMX/NOPB, LM3489QMM/NOPB, and LM3489QMMX/NOPB are direct functional equivalents to the LM3489MM. All maintain identical electrical specifications, control features, and switching frequency characteristics. These parts are in Active product status with substantially higher inventory availability (3,060 to 16,371 units). Selection among these variants depends on packaging requirements (Cut Tape vs. Tape & Reel) and qualification grade (commercial vs. automotive AEC-Q100).

Secondary Substitutes (LM3485 Series - Parametric Equivalents)

LM3485MM/NOPB, LM3485MMX/NOPB, and LM3485Q1MM/NOPB provide parametric equivalence in supply voltage range, topology, package, and operating temperature. These parts maintain the same electrical operating envelope and physical form factor. Control feature specifications and switching frequency documentation are not provided for LM3485 variants. LM3485 series parts offer the highest inventory availability (55,100 to 96,400 units) and represent long-term supply continuity.

Compliance & Qualification Considerations

All substitute parts maintain ROHS3 compliance and MSL 1 rating. Automotive-grade variants (Q-suffix parts) carry AEC-Q100 qualification. Selection should align with application requirements for automotive qualification if specified in the original design.

Frequently Asked Questions (FAQ)

Q: Can LM3489MM be directly replaced with LM3485 series parts?

A: LM3485 series parts are parametric equivalents that maintain the same supply voltage range (4.5V ~ 35V), topology (buck), package (8-VSSOP), and operating temperature (-40°C ~ 125°C). However, control feature specifications and switching frequency documentation differ. Verification against application-specific control requirements is necessary before substitution.

Q: What is the difference between LM3489MM and LM3489MM/NOPB?

A: Both parts are functionally identical. The /NOPB suffix indicates lead-free (Pb-free) and halogen-free compliance. The primary difference is product status: LM3489MM is Last Time Buy, while LM3489MM/NOPB is Active with higher inventory availability.

Q: Are packaging variants (Cut Tape vs. Tape & Reel) electrically equivalent?

A: Yes. Cut Tape (CT) and Tape & Reel (TR) packaging variants contain identical die and electrical specifications. Selection depends on assembly process requirements and volume handling procedures.

Q: What does the Q-suffix indicate in part numbers like LM3489QMM/NOPB?

A: The Q-suffix indicates automotive-grade qualification with AEC-Q100 certification. These parts meet automotive reliability and testing standards. Selection should reflect application requirements for automotive qualification.

Q: Which substitute offers the best long-term supply availability?

A: LM3485MM/NOPB provides the highest inventory (96,400 units) and Active product status, ensuring sustained availability. This part maintains parametric equivalence across all critical electrical and mechanical parameters.

Q: Can I use LM3485Q1MM/NOPB as a direct replacement in automotive applications?

A: LM3485Q1MM/NOPB carries AEC-Q100 automotive qualification and maintains the required electrical specifications and package compatibility. Verification of control feature requirements against application specifications is necessary, as control feature documentation is not provided for this part.

Request Quote (Ships tomorrow)

Part Number

Quantity

Company

Contact Name

E-mail

Message